[5] In February 1553, the company was awarded the title of "Imprimeur du Roi en musique" (previously held by Pierre Attaignant).
[6] Royal patronage was a major factor in the company's success since it ensured both a ready supply of new music from the court musicians and a market for its publications.
[6] Over the following two decades other rival companies dropped out of the market and from the 1570s onwards Le Roy & Ballard enjoyed a virtual monopoly in music publishing.
Le Roy also helped to ensure the success of composer Orlande de Lassus, introducing him to court and publishing his music.
[8] Le Roy's book L'Instruction pour la mandore gives modern historians hints as to the instruments origins and design.